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Base64 Decoder

Decode Base64 or URL-safe Base64 back to readable text, with validation.

Also known as decode base64, base64 to text, base64 decoder online.

Enter values

Results update as you type.

Result

Decoded text

Hello, World!

Decoded size
13 B
Encoded size
20 B
Characters
13
Looks like JSON
No

About the Base64 Decoder

Decode Base64 or URL-safe Base64 back to readable text, with validation.

Also known as: decode base64, base64 to text, base64 decoder online.

How to use this calculator

  1. Enter base64 to decode.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Base64 Decoder formula

Every 4 Base64 characters decode back to 3 bytes

Worked example

Using the values pre-filled in the calculator above:

  • Base64 to decode: SGVsbG8sIFdvcmxkIQ==

the calculator returns:

  • Decoded text: Hello, World!
  • Decoded size: 13 B
  • Encoded size: 20 B
  • Characters: 13